The goal of this proposed collaborative R01 randomized controlled trial is to test the effectiveness of a novel intervention, the Treatment Initiation and Participation (TIP) program, on depression treatment adherence and depression outcomes among geriatric primary care patients. TIP is a brief, psychosocial intervention aimed at reducing the multifaceted personal barriers to adhering to depression treatment. Adherence is a challenge across the lifespan, but among older adults with depression, this challenge is compounded by medical and psychiatric co-morbidity, medical regimen complexity, and skeptical attitudes towards mental illness and its care. For older adults, the effect of stigma on seeking care for mental health issues such as depression is particularly strong. The decision to begin treatment for depression entails both countering the ageist notion that depression is a normal outgrowth of aging and confronting the stigma of mental health treatment particularly prevalent in this cohort. The treatment gap created by non-adherence in later life is becoming an even more prominent issue as the nation's demographic profile shifts. The proposed RCT will be conducted with diverse community samples from two geographically complementary primary care centers (Ann Arbor, Michigan and New York City). The study will recruit 260 older adults who have been newly prescribed antidepressant medication by their primary care physician, and randomize participants to receive either the TIP intervention or usual care. To test the study hypotheses, research assessments will be conducted at study entry, and at 6, 12 and 24 weeks after enrollment. If the proposed intervention is useful in improving antidepressant adherence, it has the potential to decrease the deleterious effects of untreated depression in a growing number of older adults. As a brief manualized intervention, TIP-PC is designed to fit easily within primary care practices and to be delivered by non-MD staff.